Study: Drug combination offers hope for bipolar depression

A new combination of pre-existing drugs may have unlocked a new treatment for bipolar depression, a Columbia University study released Wednesday found.

The study suggests a way to prolong the effects of ketamine, which has been shown to be helpful in treatment-resistant bipolar depression, but its effects don't usually last more than a week or two.

Though the study only included eight subjects and did not have a control group, the preliminary findings show on average a 50% reduction in symptoms of depression and a 75% reduction in the likelihood of patients committing suicide with treatment-resistant bipolar depression.

"Bipolar depression is notoriously difficult to treat, and in the published ketamine literature, people tend to relapse within two weeks," said Joshua Kantrowitz, one of the researchers and a physician and assistant professor of psychiatry at Columbia. "This was some pilot data suggesting that D-cycloserine may be a compound that can prolong the ketamine effect."

More than 3 million Americans have bipolar depression. Those with the disease are more than twice as likely to commit suicide compared with patients who have other forms of depression. About 25% to 50% will attempt suicide in their lives.

The researchers, led by Kantrowitz, assigned all subjects to one of three commonly used drugs for bipolar depression. After about four weeks, the subjects, on average, showed no improvement in their symptoms. All the subjects then received ketamine.

The next day, the subjects began taking D-cycloserine, a drug that is often used to treat tuberculosis. The study showed D-cycloserine maintained the positive effects of ketamine over the next eight weeks of the study as the subjects remained on the commonly used drugs.

"I wouldn't argue for people to run out and put everybody on this drug yet," Kantrowitz said. "I would argue for doing a future study."

Kantrowitz said he is in the process of applying for additional funding to do a larger study.

Four of the subjects in the study were taking Lurasidone, a commonly used drug to treat bipolar depression, when D-cycloserine was administered.

The success of that pairing bodes well for NeuroRx, a new pharmaceutical company that is developing Cyclurad, a drug that combines D-cycloserine and Lurasidone into one pill.

The new drug still faces years of Food and Drug Administration testing, but its developers say the Columbia study shows promising results.

"This is just one more potential advance," said Daniel Javitt, a physician and the inventor of Cyclurad. "(Bipolar depression) is a hard disease to treat because even though people have been researching it for years, we just don't know what causes it."